Data storage capacities of various media have grown substantially with time, such that a single data storage media is capable of storing many times that of earlier media. One way of handling the data is to have the present media store multiple “logical” units of data that once were the entire capacity of the media. The concept of “logical” units of data is further carried out in the handling of the data in hierarchical data storage servers, where frequently accessed data is stored in faster but expensive memory, and less frequently accessed data is stored in high capacity but slower memory. One example of a fast memory is a direct access storage device (DASD) comprising a disk drive, or a solid state disk (SSD). Examples of high capacity memory are magnetic tape drives or libraries, and disk drive arrays, such as RAID (redundant array of independent disks), or JBOD (just a bunch of disks). Typically, a number of the logical units of data, such as logical volumes, are stored together in the faster memory, and very large numbers of logical units of data are stored together in the slower memory. The logical units of data are typically identified by volume serial numbers (VOLSERs), and may be treated as though they were being stored as “virtual” single data storage media or objects in a “virtual” data storage drive or library, whereas they are actually stored together in files or stacked in physical media.
In some instances, the data being stored is sufficiently important that it is protected from being overwritten or erased and changed or lost. Some data storage media lends itself to protecting the data, such as “read only memory” or ROM, such as ROM optical disks. Other media has an aspect of ROM, such as “Write Once Read Many” or WORM media. The incorporated '846 and '803 patents discuss how rewritable media may be treated as though it were WORM media, where the media, such as a magnetic tape cartridge, comprises two forms of memory, one the media itself, and the other a cartridge memory (CM).
One requirement of WORM media is that different instances of media having data with the same volume serial number must be detectable to protect the integrity of the data against possible malicious behavior. Where the WORM media or media that is treated as though it were WORM is in a physical media object, a world wide name embedded in the media cartridge may be employed to detect when the physical media has been replaced, thus detecting potential malicious behavior. Logical units of data that are virtual objects may be no more than files stored in the faster or slower memories of servers discussed above, and the overall lifecycle of a logical volume may introduce non-protected places where its contents can be compromised. For example, another independent server may write data with the same volume serial number which can get stacked to a physical tape cartridge. If that physical cartridge were to be relabeled and inserted falsely into the original server, its contents, including the stacked logical volume, may go undetected as different. Further, it may be possible that software issues may introduce data anomalies where logical volumes may be replaced with stale versions.